Conduit grip and process



June 27, 1967 K. J. LANG 3,328,055

CONDUIT GRIP AND PROCESS Filed June 7, 1965 F)cs.5

INVENTOR KALMAN J. LAN 6 Wim 244% AGENT United States Patent 3,328,055 CONDUIT GRIP AND PROCESS Kalman J. Lang, Gld Turnpike Road, Haddam, Conn. @6438 Filed June 7, 1965, Ser. No. 461,934 12 Claims. (Cl. 237-20) ABSTRACT OF THE DISCLOSURE A removable conduit grip and conduit grip-conduit assembly for positioning and sealing a cylindrical traversing conduit flush with the interior walls of a concrete form. The grip is a flat, circular disk with a threaded periphery, a threaded bolt hole, and a wrench engaging depression. A grip can be screwed flush into each end of a conduit having internal threading means, whereupon both ends of the resultant assembly can be bolted into place through the exterior walls of the concrete form.

This invention relates to a conduit grip adapted to hold a conduit in a removable concrete form and a method for using the same for setting conduits in concrete structures.

Water, electric and other conduits are set in structural concrete in a variety of installations where they serve for the transmission of power, heat exchange, etc. For such purposes, a conduit or conduit assembly having internal threading means at each end thereof must be set firmly in place while the concrete is poured and allowed to harden. This must be accomplished in such a manner that the internal threading is not obstructed by concrete or soiled therewith and is readily accessible for installation of connecting conduits or other fittings when the concrete forms are removed. In addition, this should be accomplished in such a manner that the concrete forms are not appreciably damaged and may be reused.

Prior art methods for supporting conduits in concrete forms include cutting holes in the forms to fit the conduit which then protrudes through the walls of the form. This procedure requires cutting large holes in the form which makes it unsatisfactory for further use. Another technique is to force wooden plugs into the supporting ends of the conduits and fasten these at the desired locations inside the form by hammering nails or spikes through the form walls from the outside. These plugs are not threaded and do not grip the coupling end of the conduit firmly flush to the form wall. As a result, they may be dislodged, bent, loosened or broken during the concrete pouring. This is particularly the case with large forms where metal vibrators are forced down into the wet concrete to insure proper filling of the form. In addition, some liquid concrete seeps around the coupling ends and soils the threading which must then be cleaned thoroughly when the forms are removed. Plugging devices which are fastened to the form walls from within are unsatisfactory since the conduit assembly including the plugging devices must be inserted in the form so that the coupling ends are flush to the form walls. Fastening from within is specially difficult when the conduit traverses opposing walls of the form unless one of the walls can be removed and then replaced to allow the fastening devices to engage with both walls. This is a very difiicult operation when large forms are involved and becomes practically impossible in cases where several conduits are to traverse the form. Additional difficulties are encountered when a conduit must enter the form at one level and leave at another or where it must execute several changes of direction within the form. This may include entry and re-entry on the same form wall or entry on one wall and exit on a wall at right angles thereto.

It is an object of this invention to provide a novel grip for alfirmatively holding the coupling ends of a conduit flush to the walls of a concrete form.

It is another object to provide grips to hold both coupling ends of a conduit flush to the walls of a concrete form which is traversed by the said conduit.

It is an additional object to provide a conduit grip whose use in combination with removable concrete forms will not render said forms unfit for reuse nor permit concrete soilage of the coupling ends.

It is also an object to provide a grip which can be used to install a conduit or conduit assembly with coupling ends at both ends to the opposing Walls of a concrete form in such a manner that the form walls do not have to be moved to admit the traversing conduit or conduitconduit grip assembly.

It is a still further object to provide a method for installing traversing conduits in concrete structures when employing removable concrete forms.

These and other objects and advantages will become apparent in the following discussion and description of the invention taken in conjunction with the accompanying drawing.

FIGURE 1 is a vertical sectional view through a section of a concrete form showing a traversing conduit supported by conduit grips embodying this invention.

FIGURE 2 is a vertical sectional view of a grip embodying this invention in the plane of line II-II of FIG. 3.

FIGURE 3 is a front elevation of the grip of FIG. 2 as seen from the plane II of its outer surface as shown in FIG. 2.

FIGURE 4 is a vertical sectional view of an alternative modified form of the conduit grip embodying this invention.

FIGURE 5 is a sectional view of a part of a concrete structure containing an embedded conduit after the concrete form and conduit grip have been removed.

Referring more particularly to the drawings, the numerals 10, 10 represent the opposing walls of a removable concrete form. Inserted between these walls is a traversing conduit assembly comprising the conduit 11 having external threads at each end fitted with standard couplings 12, 12 to provide external threading means at each end of said conduit. A conduit grip 14 embodying this invention is shown screwed into each standard coupling 12 so that the outer surface of :said grip is flush with the conduit end threading means. Bolts 16, 16 pierce form walls 10, 10 through drilled holes 17, 17 and engage the threaded bolt holes of the grips 14, 14, thus holding the conduit firmly in the concrete form.

The construction of a conduit grip embodying the invention is seen in FIG. 2 and FIG. 3. In FIG. 2, the threaded periphery 15 of the grip is tapered in such fashion that it can be screwed into the conduit end threading means to the point where it is flush with the end of said threading means but no further. Deprcssions 19 and 20 in the outer surface of the grip make it possible to receive a wrench or wrenching means whereby a rotary motion may be imparted to the grip in the act of screwing it into and out of the conduit end threading means.

FIG. 4 represents a modification of the grip of this invention having a normal thread 13 and a flange 24 which fits the flared end of the conduit end threading means so that said grip can be screwed into said means only to the point where it is flush with said end.

It is a preferred structural characteristic of the grip of this invention that it cannot. enter into the conduit end threading means further than the point at which its outer surface is flush with the end thereof. If the grip should enter said threading means to a greater depth, concrete would seep into the exposed ends of the coupling threads. The threads would then have to be cleaned after the concrete had set and the forms were removed. Such individual cleaning of the threads, which would be necessary before the embedded conduit could be connected with external fittings, would be both time consuming and expensive. On the other hand, if the grip were allowed to protrude from the conduit end by not making it flush therewith, concrete would set around the protruding threads of the grip which would make it difficult to remove after the concrete had set and would render said grip unfit for reuse without cleaning. FIG. 2 and FIG. 4 illustrate alternative means for restraining entry of the grip beyond the point where it is flush with the conduit end threading means. The use of such restraining means automatically prevents improper installation of the grips.

FIG. 5 shows the conduit assembly of FIG. 1 at one end after it has been set in concrete 21 and the form and grip have been removed leaving the conduit 11 and coupling 12, which serves as the conduit end threading means, in the concrete structure. External fitting 22 is shown attached to coupling 12 for transmission of water, electric cables, etc., as may be desired.

It should be noted that the size of the conduit grip of this invention is determined by the size of the conduit or coupling involved and may vary greatly. Although the grip shown in the drawings has but one central bolt hole, the said hole need not be in the center of the circular grip. Also, conduit grips may have a plurality of bolt holes. This is desirable in dealing with large conduits to insure adequate support. The bolt holes in the grips are always of small diameter as compared with the size of the grip since small holes drilled into the concrete form will not render said form unfit for resuse.

Although the grip of this invention is preferably made of metal, it may also be fabricated of tough plastic, laminated materials or any substance of suitable strength which can be machined or cast into the desired form.

It should also be noted that although the use of standard conduits with external threading plus standard coupling-s with internal threading to supply internal threading means at the conduit ends is most common, a conduit with internal threading at each end could be used. In this case, the conduit ends would receive the conduit grip directly and externally threaded fittings would be employed for outside connection with the conduit as set in the concrete structure.

A special advantage resulting from the use of the conduit grips of this invention for holding conduits traversing concrete forms lies in the fact that such use imparts added strength to the form walls against outward spreading as well as inward compression.

The process of installing conduits in a concrete structure by the procedure of this invention involves providing a conduit of the size desired with internal threading means at each end and of such length that it will fit into the concrete form with its ends substantially flush therewith at the desired points of traverse. For example, an assembly comprising an externally threaded conduit 11 and two standard couplings 12, 12 with internal threading is fabricated. Conduit grips 14, 14 are then screwed into the externally threaded ends of the conduit assembly so that the outer surfaces of said grips are flush with said ends. The conduit-conduit grip assembly is then lowered into the concrete form to the desired points of traverse and bolted tightly in place as shown in FIG. 1 by passing bolts 16, 16 through drilled holes 17, 17 in the form walls 10, engaging bolt holes 18, 18 in said grips 14, 14. Adjustment of the bolts is facilitated by entry of the bolt ends in the threaded holes 18, 18 of the grips as soon as they are partially aligned. When the grips have been tightened, the concrete is poured into the form surrounding the conduit while using a vibrator, if necessary, to assure thorough filling of the form. After the concrete has set, bolts 16, 16 and form Walls 10, 10 are removed. The conduit grips 14, 14 are then removed with a suitable wrench or wrenching means by entry in depressions 19 and 29 in the outer surface of said grips. This leaves clean, accessible coupling ends flush with the concrete as shown in FIG. 5. Link fittings such as 22 may then be installed.

Although the conduit grip of this invention and its use have been described in specific form, this has been done solely for purposes of illustration. Numerous changes in the details of construction and method may be resorted to without departing from the scope of the invention as claimed.

What is claimed is:

1. A circular grip adapted for use in combination with a cylindrical conduit having internal threading means at both ends to hold said conduit in a concrete form by means of external bolts piercing said form from without, said grip having a flat outer surface, a fiat inner surface, an externally threaded periphery such that said grip may be screwed into the aforesaid conduit threading means to the point where said outer surface is flush with the end thereof, a threaded bolt hole of relatively small diameter with respect to said grip whereby it may be bolted afiirmatively to the aforesaid concrete form, and depressions in the outer surface of said grip to receive wrenching means.

2. A circular grip adapted for use in combination with a cylindrical conduit having internal threading means at both ends to hold said conduit in a concrete form by means of external bolts piercing said form from without, said grip comprising a circular disk having a flat outer surface, a flat inner surface, an externally threaded periphery with restraining means such that said grip may be screwed into the aforesaid conduit threading means only to the point where said outer surface is flush with the end thereof, a threaded bolt hole of relatively small diameter with respect to said grip whereby it may be bolted affirmatively to the aforesaid concrete form, and depressions in the outer surface of said grip to receive wrenching means.

3. A circular grip adapted for use in combination with a cylindrical conduit having internal threading means at both ends to hold said conduit in a concrete form by means of external bolts piercing said form from without, said grip comprising a circular disk having a flat outer surface, an inner surface, an externally threaded periphery wherein the thread is tapered so that it may be screwed into the aforesaid conduit threading means only to the point where said outer surface is flush with the end thereof, a threaded bolt hole of relatively small diameter with respect to said grip whereby it may be bolted afiirmatively to the aforesaid concrete form, and depressions in the outer surface of said grip to receive wrenching means.

4. A circular grip adapted for use in combination with a cylindrical conduit having internal threading means at both ends to hold said conduit in a concrete form by means of external bolts piercing said form from without, said grip comprising a circular disk having a flat outer surface, a flat inner surface, an externally threaded periphery having a flange adjacent to said outer surface such that said grip may be screwed into the aforesaid conduit threading means only to the point where said outer surface is flush with the end thereof, a threaded bolt hole of relatively small diameter with respect to said grip whereby it may be bolted affirmatively to the aforesaid concrete form, and depressions in the outer surface of said grip to receive wrenching means.

5. The conduit grip of claim 2 having a central threaded bolt hole of relatively small diameter with respect to said grip.

6. The grip of claim 2 having a plurality of threaded bolt holes of relatively small diameter with respect to said grip.

7. A conduit-conduit grip assembly for traversing a concrete form wherein the ends are flush with the opposing form walls, said assembly comprising a cylindrical conduit with internal threading means at each end thereof and removable conduit grips screwed into said internal threading means to the point where the outer surface of each grip is flush with the ends of conduit threading means, said grips each comprising, in combination, a circular disk having a flat outer surface, a flat inner surface, an externally threaded periphery such that it may be screwed into the aforesaid conduit threading means, depressions in the outer surface of said grip to receive wrenching means, and a threaded bolt hole of relatively small diameter, whereby the aforesaid assembly may be bolted affirmatively flush to said opposing form walls from without by bolts passing through said form walls into the bolt holes of said grips and held in place during the pouring and hardening of concrete in said form after which said bolts, said form walls, and said grips may be removed leaving said conduit set in concrete with threading means flush to the surface.

8. The conduit-conduit grip assembly of claim 7 wherein the externally threaded periphery of each conduit grip is provided with restraining means such that said grip may be screwed into the conduit threading means only to the point where the outer surface of said grip is flush with the end thereof.

9. The conduit-conduit grip assembly of claim 7 wherein the externally threaded periphery of each conduit grip is tapered so that it maybe screwed into the conduit threading means only to the point where the outer surface of said grip is flush to the end thereof.

10. The conduit-conduit grip assembly of claim 7 wherein the externally threaded periphery of each conduit grip is provided with a flange adjacent to its outer surface such that said grip may :be screwed into the conduit threading means only to the point where the outer surface of said grip is flush to the end thereof.

11. The conducit-conduit grip assembly of claim 8 wherein the threaded bolt hole of each conduit grip is in the center thereof.

12. The conduit-conduit grip assembly of claim 8 wherein each grip has a plurality of threaded bolt holes of relatively small diameter with respect to said grip.

References Cited UNITED STATES PATENTS 1,309,084 7/ 1919 Zimmerman 249-177 1,822,444 9/ 1931 MacClatchie 285425 1,908,796 5/1933 Su'chan 249-177 2,801,023 7/1957 Baker el al. 138-89 3,157,203 5/1961 Vernooy 13889 3,236,342 2/ 1963 Persson 287-20 CARL W. TOMLIN, Primary Examiner.

W. L. SHEDD, Assistant Examiner. 

1. A CIRCULAR GRIP ADAPTED FOR USE IN COMBINATION WITH A CYLINDRICAL CONDUIT HAVING INTERNAL THREADING MEANS AT BOTH ENDS TO HOLD SAID CONDUIT IN A CONCRETE FORM BY MEANS OF EXTERNAL BOLTS PIERCING SAID FORM FROM WITHOUT, SAID GRIP HAVING A FLAT OUTER SURFACE, A FLAT INNER SURFACE, AN EXTERNALLY THREADED PERIPHERY SUCH THAT SAID GRIP MAY BE SCREWED INTO THE AFORESAID CONDUIT THREADING MEANS TO THE POINT WHERE SAID OUTER SURFACE IS FLUSH WITH THE END THEREOF, A THREADED BOLT HOLE OF RELATIVELY SMALL DIAMETER WITH RESPECT TO SAID GRIP WHEREBY IT MAY BE BOLTED AFFIRMATIVELY TO THE AFORESAID CONCRETE FORM, AND DEPRESSIONS IN THE OUTER SURFACE OF SAID GRIP TO RECEIVE WRENCHING MEANS. 